Abnormality judgment device and abnormality judgment method of power supply unit

Abstract

In a power supply unit comprising a battery (2) for supplying power to an electric load (6), a current sensor (4) for detecting the current of the battery (2), and a voltage sensor (5) for detecting the voltage of the battery (2), a decision is made that open fault has occurred in the battery (2) if a voltage detected by the voltage sensor (5) is larger than a predetermined first variation and a current detected by the current sensor (4) is smaller than a predetermined second variation, and a decision is made that intermediate fixed fault has occurred in the current sensor (4) if a decision is not made that open fault has occurred in the battery (2) and when the internal resistance of the battery (2) is not lower than a predetermined value.

Description

Technical field [0001] The present invention relates to an abnormality determination device and an abnormality determination method of a power supply device including a battery and a current sensor for detecting battery current. Background technique [0002] Conventionally, a current sensor failure determination device has been widely known for determining a failure of a current sensor that detects the current of a battery that supplies power to an electric load (for example, refer to Patent Document 1). This fault judgment device focuses on the phenomenon that the battery voltage decreases due to the internal resistance of the battery when the battery current increases. That is, the variation of the battery current when the battery voltage only fluctuates by the standard variation is detected, and when the variation of the battery current is less than or equal to the standard value, the battery current that should have changed is considered to be in a non-variable state due to t...

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Problems solved by technology

[0004] However, in the above-mentioned prior art, there is a problem as follows: Even if the current sensor is normal, when a battery open-circuit failure such as battery terminal detachment occurs, the power consumption of the electric load will change due to the loss of the voltage stabilization effect of the battery, etc. The cause causes the battery voltage (that is, the voltage applied to the electric load) to fluctuate beyond the above-mentioned standard fluctuation, and because the battery is not charged and discharged, the fluctuation of the battery current will become below the above-mentioned standard value

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